Finished Release v1.3.0

CHANGELOG.md

@@ -1,6 +1,11 @@
 Change Log
 ==========
 
+v1.3.0
+------
+- Support LowCardinality columns in ad-hoc queries
+- Support for LIMIT BY in querysets (utapyngo)
+
 v1.2.0
 ------
 - Add support for per-field compression codecs (rbelio, Chocorean)

docs/class_reference.md

@@ -890,6 +890,14 @@ Adds a FINAL modifier to table, meaning data will be collapsed to final version.
 Can be used with `CollapsingMergeTree` engine only.
 
 
+#### limit_by(offset_limit, *fields)
+
+
+Adds a LIMIT BY clause to the query.
+- `offset_limit`: either an integer specifying the limit, or a tuple of integers (offset, limit).
+- `fields`: the field names to use in the clause.
+
+
 #### only(*field_names)
 
 
@@ -1013,6 +1021,14 @@ be names of grouping fields or calculated fields that this queryset was
 created with.
 
 
+#### limit_by(offset_limit, *fields)
+
+
+Adds a LIMIT BY clause to the query.
+- `offset_limit`: either an integer specifying the limit, or a tuple of integers (offset, limit).
+- `fields`: the field names to use in the clause.
+
+
 #### only(*field_names)
 
 

scripts/generate_ref.py

@@ -52,8 +52,6 @@ def get_method_sig(method):
         default_arg = _get_default_arg(argspec.args, argspec.defaults, arg_index)
         if default_arg.has_default:
             val = default_arg.default_value
-            if isinstance(val, basestring):
-                val = '"' + val + '"'
             args.append("%s=%s" % (arg, val))
         else:
             args.append(arg)
@@ -73,45 +71,45 @@ def docstring(obj):
         indentation = min(len(line) - len(line.lstrip()) for line in lines if line.strip())
         # Output the lines without the indentation
         for line in lines:
-            print line[indentation:]
-        print
+            print(line[indentation:])
+        print()
 
 
 def class_doc(cls, list_methods=True):
     bases = ', '.join([b.__name__ for b in cls.__bases__])
-    print '###', cls.__name__
-    print
+    print('###', cls.__name__)
+    print()
     if bases != 'object':
-        print 'Extends', bases
-        print
+        print('Extends', bases)
+        print()
     docstring(cls)
-    for name, method in inspect.getmembers(cls, inspect.ismethod):
+    for name, method in inspect.getmembers(cls, lambda m: inspect.ismethod(m) or inspect.isfunction(m)):
         if name == '__init__':
             # Initializer
-            print '####', get_method_sig(method).replace(name, cls.__name__)
+            print('####', get_method_sig(method).replace(name, cls.__name__))
         elif name[0] == '_':
             # Private method
             continue
-        elif method.__self__ == cls:
+        elif hasattr(method, '__self__') and method.__self__ == cls:
             # Class method
             if not list_methods:
                 continue
-            print '#### %s.%s' % (cls.__name__, get_method_sig(method))
+            print('#### %s.%s' % (cls.__name__, get_method_sig(method)))
         else:
             # Regular method
             if not list_methods:
                 continue
-            print '####', get_method_sig(method)
-        print
+            print('####', get_method_sig(method))
+        print()
         docstring(method)
-        print
+        print()
 
 
 def module_doc(classes, list_methods=True):
     mdl = classes[0].__module__
-    print mdl
-    print '-' * len(mdl)
-    print
+    print(mdl)
+    print('-' * len(mdl))
+    print()
     for cls in classes:
         class_doc(cls, list_methods)
 
@@ -128,9 +126,9 @@ if __name__ == '__main__':
     from infi.clickhouse_orm import models
     from infi.clickhouse_orm import query
 
-    print 'Class Reference'
-    print '==============='
-    print
+    print('Class Reference')
+    print('===============')
+    print()
     module_doc([database.Database, database.DatabaseException])
     module_doc([models.Model, models.BufferModel, models.DistributedModel])
     module_doc(sorted([fields.Field] + all_subclasses(fields.Field), key=lambda x: x.__name__), False)

src/infi/clickhouse_orm/models.py

@@ -88,6 +88,10 @@ class ModelBase(type):
         if db_type.startswith('Nullable'):
             inner_field = cls.create_ad_hoc_field(db_type[9 : -1])
             return orm_fields.NullableField(inner_field)
+        # LowCardinality
+        if db_type.startswith('LowCardinality'):
+            inner_field = cls.create_ad_hoc_field(db_type[15 : -1])
+            return orm_fields.LowCardinalityField(inner_field)
         # Simple fields
         name = db_type + 'Field'
         if not hasattr(orm_fields, name):

src/infi/clickhouse_orm/query.py

@@ -293,6 +293,8 @@ class QuerySet(object):
         self._grouping_with_totals = False
         self._fields = model_cls.fields().keys()
         self._limits = None
+        self._limit_by = None
+        self._limit_by_fields = None
         self._distinct = False
         self._final = False
 
@@ -332,6 +334,23 @@ class QuerySet(object):
             qs._limits = (start, stop - start)
             return qs
 
+    def limit_by(self, offset_limit, *fields):
+        """
+        Adds a LIMIT BY clause to the query.
+        - `offset_limit`: either an integer specifying the limit, or a tuple of integers (offset, limit).
+        - `fields`: the field names to use in the clause.
+        """
+        if isinstance(offset_limit, six.integer_types):
+            # Single limit
+            offset_limit = (0, offset_limit)
+        offset = offset_limit[0]
+        limit = offset_limit[1]
+        assert offset >= 0 and limit >= 0, 'negative limits are not supported'
+        qs = copy(self)
+        qs._limit_by = (offset, limit)
+        qs._limit_by_fields = fields
+        return qs
+
     def select_fields_as_sql(self):
         """
         Returns the selected fields or expressions as a SQL string.
@@ -366,6 +385,10 @@ class QuerySet(object):
         if self._order_by:
             sql += '\nORDER BY ' + self.order_by_as_sql()
 
+        if self._limit_by:
+            sql += '\nLIMIT %d, %d' % self._limit_by
+            sql += ' BY %s' % comma_join('`%s`' % field for field in self._limit_by_fields)
+
         if self._limits:
             sql += '\nLIMIT %d, %d' % self._limits
 

tests/base_test_with_data.py

@@ -35,7 +35,7 @@ class TestCaseWithData(unittest.TestCase):
 class Person(Model):
 
     first_name = StringField()
-    last_name = StringField()
+    last_name = LowCardinalityField(StringField())
     birthday = DateField()
     height = Float32Field()
     passport = NullableField(UInt32Field())

tests/test_database.py

@@ -209,3 +209,12 @@ class DatabaseTestCase(TestCaseWithData):
         # Remove the setting and see that now it works
         self.database.add_setting('max_columns_to_read', None)
         list(self.database.select('SELECT * from system.tables'))
+
+    def test_create_ad_hoc_field(self):
+        # Tests that create_ad_hoc_field works for all column types in the database
+        from infi.clickhouse_orm.models import ModelBase
+        query = "SELECT DISTINCT type FROM system.columns"
+        for row in self.database.select(query):
+            if row.type in ('IPv4', 'IPv6'):
+                continue # unsupported yet
+            ModelBase.create_ad_hoc_field(row.type)

tests/test_querysets.py

@@ -432,6 +432,23 @@ class AggregateTestCase(TestCaseWithData):
         qs = Mdl.objects_in(self.database).filter(the__next__number__gt=1)
         self.assertEqual(qs.conditions_as_sql(), 'the__next__number > 1')
 
+    def test_limit_by(self):
+        # Test without offset
+        qs = Person.objects_in(self.database).aggregate('first_name', 'last_name', 'height', n='count()').\
+            order_by('first_name', '-height').limit_by(1, 'first_name')
+        self.assertEqual(qs.count(), 94)
+        self.assertEqual(list(qs)[89].last_name, 'Bowen')
+        # Test with limit and offset, also mixing LIMIT with LIMIT BY
+        qs = Person.objects_in(self.database).filter(height__gt=1.67).order_by('height', 'first_name')
+        limited_qs = qs.limit_by((0, 3), 'height')
+        self.assertEquals([p.first_name for p in limited_qs[:3]], ['Amanda', 'Buffy', 'Dora'])
+        limited_qs = qs.limit_by((3, 3), 'height')
+        self.assertEquals([p.first_name for p in limited_qs[:3]], ['Elton', 'Josiah', 'Macaulay'])
+        limited_qs = qs.limit_by((6, 3), 'height')
+        self.assertEquals([p.first_name for p in limited_qs[:3]], ['Norman', 'Octavius', 'Oliver'])
+
+
+
 
 Color = Enum('Color', u'red blue green yellow brown white black')